The invention relates to a temperature sensor, which has an at least partly rod-shaped construction, in which appropriately two or more components have different thermal expansion coefficients, so that a sensing value can be derived from the relative expansion. The components are supported against one another by means of one or more abutments.
Temperature sensors of this type can, in the form of rod sensors, be fixed to one or more switch bases or casings and project freely to the outside. One or more inner rods made from an insulating material, such as steatite, or a metal are placed in one or more outer tubes made from metal or insulating material, such as quartz glass. These two or more rod units are supported against one another by means of an abutment at the rod sensor end remote from the switch base, while the end of a rod part located at the switch base is used for switch operation and the associated end of the other rod part for fixing with respect to the switch base. Such temperature switches are mainly used as thermal cutouts and/or signal switches or the like on heating appliances, such as electric hotpoints, etc. For adjusting the temperature sensor, the abutment can be formed by a screwbolt that is adjusted in the direction of the operating movement of the temperature sensor and is then fixed optionally with a varnish coating. The torque needed for adjustment purposes can vary very widely as a function of the thread quality and thread tolerances. In addition, the thread quality of the internal thread provided on the outer tube can only be fixed within very large tolerances due to the difficultly caused by deformable tube material, and there is an influence caused by wear to the threading tool, which is very considerable and takes place rapidly. The poor thread quality in particular affects the thread flanks and tolerance divergences of the minor diameter of the thread.